U.S. patent number 4,674,795 [Application Number 06/883,963] was granted by the patent office on 1987-06-23 for chair frame.
Invention is credited to Jonathan M. Nelson.
United States Patent |
4,674,795 |
Nelson |
June 23, 1987 |
**Please see images for:
( Certificate of Correction ) ** |
Chair frame
Abstract
A chair frame for supporting a seat and seat back in a novel
manner. The material of the seat, such as fabric or leather, is
supported by the frame in partial tension to avoid sagging and to
allow independent torsional movement of the seat portions
supporting each leg of the chair user. The chair frame geometry and
the tensioned seat provide a flexible chair that provides a new
seating experience that combines lounge and rocking chair type
characteristics. Additionally, the chair frame can be provided as a
one piece rigid frame or a stackable, foldable, or collapsible
frame.
Inventors: |
Nelson; Jonathan M. (Kingston,
PA) |
Family
ID: |
25383679 |
Appl.
No.: |
06/883,963 |
Filed: |
July 10, 1986 |
Current U.S.
Class: |
297/239; 297/294;
297/440.22; 297/440.24; 297/452.2 |
Current CPC
Class: |
A47C
3/023 (20130101); A47C 5/10 (20130101); A47C
5/04 (20130101); A47C 3/04 (20130101) |
Current International
Class: |
A47C
5/04 (20060101); A47C 3/04 (20060101); A47C
5/10 (20060101); A47C 3/00 (20060101); A47C
5/00 (20060101); A47C 003/04 () |
Field of
Search: |
;297/239,294,295,296,440,445 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
560673 |
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Oct 1932 |
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DE2 |
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827845 |
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Jan 1952 |
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DE |
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511307 |
|
Aug 1939 |
|
GB |
|
596913 |
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Jun 1948 |
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GB |
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Primary Examiner: Zugel; Francis K.
Attorney, Agent or Firm: Benasutti and Murray
Claims
I claim:
1. A chair frame, comprising:
(a) a base;
(b) a seat back member;
(c) two side compression support members connected to said base and
to said seat back member;
(d) center diagonal tension member connected to said base; and
(e) a cantilever seat frame defining a seat portion of the chair
frame, including:
(i) a cantilever rear outer seat frame member located in a
substantially horizontal plane and rigidly affixed to each of said
side compression support members at substantially the center of
said seat portion;
(ii) two support members, each one of which is connected to said
cantilever rear outer seat frame member at one of the points where
said outer seat frame member is rigidly affixed to each of said
side compression support members; and
(iii) a front outer seat frame member which extends downward and
across from said two support members and is connected to said
center diagonal tension member and to said support members.
2. The chair frame of claim 1, wherein each of said side support
members is capable of independent torsional movement.
3. The chair frame of claim 1, wherein portions of said base extend
outward adjacent to the connection of said base and said side
compression support members, so that a plurality of said chair
frames are stackable.
4. A collapsible chair frame, comprising:
(a) a base;
(b) a seat back member;
(c) two side compression support members connected to said seat
back member and connected to said base by removable sleeves;
(d) a center diagonal tension member removably connected to said
base; and
(e) a cantilever seat frame defining a seat portion of the
collapsible chair frame, including:
(i) a cantilever rear outer seat frame member pivotably attached to
each of said side compression support members at substantially the
center of said seat portion;
(ii) two horizontal side leg supports, each one of which is
connected to said cantilever rear outer seat frame member at one of
the points where said cantilever rear outer seat frame member is
pivotably attached to each of said side compression support
members; and
(iii) a front outer seat frame member which depends downwardly and
across from said two horizontal side leg supports and is removably
connected to said center diagonal tension member.
5. The collapsible chair frame of claim 4, wherein each of said
removable sleeves comprise a tubular member having threaded
openings substantially transverse to the sleeve longitudinal axis
for receiving fastening screws to hold said sleeve in contact with
said side compression support member and said base.
6. The collapsible chair frame of claim 4, wherein said diagonal
tension member comprises threaded openings at both ends of the
tension member, said openings being substantially transverse to the
longitudinal axis of the tension member and capable of receiving
fastening means to hold said tension member in contact with said
base and said front outer seat frame member, whereby removal of
said fastening means allows separation of said tension member from
said chair frame.
7. The collapsible chair frame of claim 4, wherein said cantilever
seat frame is rotatably attached to each of said side compression
support member by a pivot assembly.
8. The collapsible chair frame of claim 4, wherein each of said
horizontal side leg supports is capable of independent torsional
movement.
9. A foldable chair frame, comprising:
(a) a base;
(b) a seat back member;
(c) two side compression support members connected to said seat
back member and connected to said base by removable sleeves;
(d) a center diagonal tension member rotatably connected to said
base; and
(e) a cantilever seat frame defining a seat portion of the foldable
chair frame, including:
(i) a cantilever rear outer seat frame member pivotably attached to
each of said side compression support members at substantially the
center of said seat portion;
(ii) two horizontal side leg supports, each one of which is
connected to said cantilever rear outer seat frame member at one of
the points where said cantilever rear outer seat frame member is
pivotably attached to each of said side compression support
members; and
(iii) a front outer seat frame member which depends downwardly and
across from said horizontal side leg supports and is rotatably
connected to said center diagonal tension member.
10. The foldable chair frame of claim 9, wherein each of said
removable sleeves comprise a tubular member having threaded
openings substantially transverse to the sleeve longitudinal axis
for receiving fastening screws to hold said sleeve in contact with
said side compression support member and said base.
11. The foldable chair frame of claim 9, wherein said cantilever
seat frame is rotatably attached to each of said side compression
support members by a pivot assembly.
12. The foldable chair frame of claim 9, wherein each of said
horizontal side leg supports is capable of independent torsional
movement.
13. The foldable chair frame of claim 9, wherein said center
diagonal tension member rotatably connected to said base further
comprises a pair of collars, each of which is welded to said base
and rotatably connected to said tension member.
14. The foldable chair frame of claim 9, wherein said front outer
seat frame member rotatably connected to said center diagonal
tension member further comprises a pair of collars, each of which
is welded to said front outer seat frame member and rotatably
connected to said tension member.
Description
BACKGROUND OF THE INVENTION
This invention relates to a chair frame, which creates a cantilever
seat with individual leg support portions capable of independent
motion to provide maximum comfort, while providing support for the
material, such as fabric or leather, of the seat and seat back.
Fabric chairs typically provide a fabric seat slung from a chair
frame surrounding the periphery of the fabric. This arrangement is
often uncomfortable because the seat sags in the middle and cannot
provide independent leg support for each leg to correspond to the
movement of a person seated on the chair.
Additionally, steel chair frames are typically rigid and
unforgiving, and therefore they do not allow for shifting of the
users weight, changes in seated posture, or rocking movement of the
user.
SUMMARY OF THE INVENTION
It is accordingly an object of the present invention to provide a
chair frame for supporting a fabric or leather seat and seat
back.
It is another object of the present invention to provide a chair
frame that can support a fabric or leather seat partially in
tension to avoid sagging of the front portion of the fabric or
leather seat.
It is a further object of the present invention to provide a chair
frame that can support a seat that allows independent torsional
movement of the portions of the seat that support a user's
legs.
It is still another object of the present invention to provide a
chair frame that can be used with easily changeable fabric or
leather seats and seat backs.
It is yet a further object of the present invention to provide a
chair frame that gives the appearance of being made from a single
continuous piece of metal.
It is an additional object of the present invention to provide a
chair frame that is collapsible by separating the frame into
several component parts.
It is a still further object of the present invention to provide a
chair frame that can be folded substantially flat.
It is yet another object of the present invention to provide rigid
chair frames that are stackable.
The present invention provides a chair frame that can support a
fabric or leather seat and fabric or leather seat back in a novel
manner. The front part of the fabric seat is supported in tension
with the front frame bar lower than the seat to reduce interference
with a users legs by minimizing sagging so that the legs of the
chair user are supported above the metal support frame. This allows
the portion of the seat supporting each leg to be capable of
independent torsional movement for maximum comfort of the chair
user. The geometry of this chair allows for chair flexure in
response to a particular users chair posture and individual seating
requirements, such as rocking movement of the user, without the
danger of the chair turning over. This danger is avoided because
the chair base never leaves contact with the floor since any
movement is taken up in the flexure of chair frame members located
above the base. Additionally, minor modifications permit the chair
frame to be made stackable, collapsible or foldable.
The invention features, in one aspect, a chair frame having a base,
a seat back member, two side compression support members connected
to the base and continuous with the seat back member, a center
diagonal tension member connected to the base, and a cantilever
seat frame that defines a seat portion of the chair frame. The
chair frame includes a cantilevered rear outer seat frame member
located in a substantially horizontal plane and rigidly affixed to
each of the side compression support members at substantially the
center of the seat portion. The seat frame also includes two
horizontal side leg supports, each one of which is connected to the
cantilevered rear outer seat frame at one of the points where the
outer seat frame member is rigidly affixed to each of the side
compression support members. Finally, the seat frame includes a
front outer seat frame member which extends vertically downward and
across from the two horizontal side leg supports and is connected
to the center diagonal tension member.
In preferred embodiments of the chair frame each of the horizontal
side leg supports is capable of independent torsional movement via
the split front outer seat frame member. The chair base extends
outward at the point where the base and the side compression
support members are connected so that a plurality of the chair
frames are stackable.
The invention features, in another aspect, a collapsible chair
frame having a base, a seat back member, two side compression
support members connected continuous with the seat back member and
connected to the base by removable sleeves, a center diagonal
tension member removably connected to the base, and a cantilever
seat frame that defines a seat portion of the collapsible chair
frame. The collapsible chair frame includes a cantilever rear outer
seat frame member located in a substantially horizontal plane and
rotatably attached to each of the side compression support members
at substantially the center of the seat portion. The collapsible
chair frame also includes two horizontal side leg supports, each
one of which is connected to the cantilever rear outer seat frame
member at one of the points where the cantilevered rear outer seat
frame member is rotatably attached to each of the side compression
support members. Finally, the collapsible seat frame includes a
front outer seat frame member which extends vertically downward and
across from the two horizontal side leg supports and is removably
connected to the center diagonal tension member.
In preferred embodiments of the collapsible chair frame each of the
removable sleeves includes a tubular member having threaded
openings substantially transverse to the sleeve's longitudinal axis
for receiving fastening screws to hold the sleeve in contact with
the side compression support member and the base. The diagonal
tension member of the collapsible ohair frame includes threaded
openings at both ends of the tension member; the openings are
substantially transverse to the longitudinal axis of the tension
member and capable of receiving fastening screws to hold the
tension member in contact with the base and the front outer seat
frame member, so that removal of the fastening screws allows
separation of the tension member from the chair frame. The
cantilevered seat frame of the collapsible chair frame is rotatably
attached to each of the side compression support members by a pivot
assembly. Each of the horizontal side leg supports of the
collapsible chair frame is capable of independent torsional
movement.
The invention features, in still another aspect, a foldable chair
frame having a base, a seat back member, two side compression
support members connected to the seat back member and connected to
the base by removable sleeves, a center diagonal tension member
rotatably connected to the base, and a cantilever seat frame
defining a seat portion of the foldable chair frame. The foldable
chair frame includes a cantilevered rear outer seat frame member
located in a substantially horizontal plane and rotatably attached
to each of the side compression support members at substantially
the center of the seat portion. The foldable chair frame also
includes two horizontal side leg supports, each one of which is
connected to the cantilevered rear outer seat frame member at one
of the points where the rear outer seat frame member is rotatably
attached to each of the side compression support members. Finally,
the foldable chair frame includes a front outer seat frame member
which extends vertically downward and across from the horizontal
side leg supports and is rotatably connected to the center diagonal
tension member.
In preferred embodiments of the foldable chair frame each of the
removable sleeves includes a tubular member having threaded
openings substantially transverse to the sleeve longitudinal axis
for receiving fastening screws to hold the sleeve in contact with
the side compression support member and the base. The cantilevered
seat frame of the foldable chair frame is rotatably attached to
each of the side compression support members by a pivot assembly.
Each of the horizontal side leg supports of the foldable chair
frame is capable of independent torsional movement. The end of the
center diagonal tension member of the foldable chair frame which is
rotatably connected to the base further includes a pair of collars;
each collar is welded to the base and rotatably connected to the
tension member. The end of the center diagonal tension member of
the foldable chair frame which is rotatably connected to the front
outer seat frame member further includes a pair of collars; each
collar is welded to the front outer seat frame member in rotatably
connected to the tension member.
All the features and advantages of the invention will be apparent
from the following detailed description of the preferred
embodiments and from the claims.
For a full understanding of the present invention, reference should
now be made to the following description and the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a preferred embodiment of the chair
frame which is fully welded and stackable.
FIG. 2 is a side view of the chair frame shown in FIG. 1 with
phantom chairs shown stacked.
FIG. 3 is a top plan view of the chair frame shown in FIG. 1.
FIG. 4 is a perspective view of an alternate embodiment of the
chair frame which is collapsible and separable into several
parts.
FIG. 5 is an exploded view of the pivot arrangement shown in FIG.
4.
FIG. 6 is an enlarged view of the pivot arrangement shown in FIGS.
4, 5 and 10.
FIG. 7 is a cross-sectional view of the center diagonal tension
member shown in FIG. 4 taken along lines 7--7 of FIG. 4.
FIG. 8 is a cross-sectional view of the removable sleeve shown in
FIG. 4 taken along line 8--8 of FIG. 4.
FIG. 9 is a cross-sectional view of the removable sleeve shown in
FIG. 8 taken along line 9--9 of FIG. 8.
FIG. 10 is a perspective view of another alternate embodiment of
the chair frame which is foldable.
FIG. 11 is a cross-sectional view of the rotatable collar shown in
FIG. 10 taken along line 11--11 of FIG. 10.
FIG. 12 is a cross-seotional view of the rotatable oollar shown in
FIG. 11 taken along line 12--12 of FIG. 11.
FIG. 13 is a side view of the chair frame shown in FIG. 4 shown
collapsed into its removable parts.
FIG. 14 is a side view of the chair frame shown in FIG. 10 shown in
its folded position.
FIG. 15 is another alternate embodiment of the chair frame which is
fully welded but not stackable.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 3, there is shown a perspective and top
plan view respectively, of a preferred embodiment of the chair
frame, generally designated 10. Chair frame 10 includes a base 12,
two side compression support members 14, a seat back member 16,
center diagonal tension member 18, and cantilever seat frame 20.
Cantilever seat frame 20 defines a seat portion which has
cantilever rear outer seat frame member 22, two horizontal side leg
supports 24 and front outer seat frame member 26. The frame in the
general vicinity of the junction of the base member 12 and the two
side compression support members 14, designated 28, is bent
slightly outward. Additionally, welded joints 30 are provided for
attaching the two side compression support members 14 to the
cantilever seat frame 20.
The use and operation of the preferred embodiment of the chair
frame, shown in FIGS. 1 and 3, will now be described. A flexible
material seat back (not shown), typically made of fabric or
leather, is held in place by VELCRO material or other means known
to those in the art and is placed over the seat back member 16. A
flexible material seat (not shown), typically made of fabric or
leather, is also attached to the cantilever rear outer seat frame
member 22 and to the two horizontal side leg supports 24 of the
cantilever seat frame 20. The rear section of the fabric or leather
seat can be held in place with VELCRO material, snaps, tensioned
cable or any other fastener which will be known to those in the
art. The front section of the fabric or leather seat will be held
in place on the cantilever seat frame 20 by a tension rope (not
shown) extending around the circumference of seat frame 20 and
running through loops or straps which overlap the frame and are
held around the frame via the tensioned rope. The use of a fabric
or leather seat back held in place by VELCRO material and a fabric
or leather seat held in place by both VELCRO material and a tension
rope allows easy removal of the seat back and the seat for cleaning
and for changing to fabric or leather seats and seat backs of
different colors.
Once the fabric or leather seat back and seat are attached to seat
back member 16 and cantilevered seat frame 20 respectively, the
chair frame 10 can support a user. A user sitting on the fabric or
leather seat attached to cantilever seat frame 20 will find most of
his/her weight supported by cantilevered rear outer seat frame
member 22 located behind joints 30. This will cause both horizontal
side leg supports 24 and front outer seat frame member 26 to be in
torsion. The center diagonal tension member 18 will counteract the
forces in the horizontal side leg supports 24 and the front outer
seat frame member 26. However, the unsupported periphery of both
horizontal side leg supports 24 and front outer seat frame member
26 allow independent torsional movement of each side leg support 24
and the front outer seat frame member 26 to provide maximum comfort
for the user. Additionally, front outer seat frame member 26 is
generally U-shaped and extends downward from the front of the side
leg supports 24. This allows the seat fabric or leather, stretched
in tension between the two horizontal side leg supports 24, to
support the user's legs above the front outer seat frame member
26.
When chair frames 10, with or without fabric or leather seat backs
and fabric seats, are not in use they can be stacked for convenient
storage as shown in FIG. 2. Outward extensions 28 of the frame
allow chair frames 10 to be easily slipped over one another for
stacking. Alternatively, chair frame 10 can be provided without
outward extensions 28, as shown in FIG. 15 by the chair frame
generally designated 32. The embodiment of the chair frame shown in
FIG. 15 operates the same as chair frame 10 except that a plurality
of frames 32 cannot be stacked when not in use.
In an alternate embodiment of the invention the chair frame can be
provided as a collapsible frame. Referring to FIG. 4, a collapsible
chair frame, generally designated 34, is shown. Chair frame 34 is
substantially the same as chair frame 10 in geometry and operation.
The only difference is that chair frame 34 can be separated into
several pieces and collapsed as shown in FIG. 13.
Chair frame 34 includes two removable sleeves 36 (shown in FIGS. 8
and 9) into which base 12 and side compression support members 14
are inserted. Referring to FIGS. 8 and 9, removable sleeves 36 each
include two fastening screws 38 which thread into threaded openings
extending through the sleeve 36. Screws 38 when threaded into the
openings in sleeve 36 extend into indentations 40 in base member 12
and side compression support members 14 and hold the members
together.
Center diagonal tension member 18 is also provided with removable
attachment means at each end. Referring to FIG. 7, a cross-section
of one end of tension member 18 shows the attachment means located
at each end of tension member 18. The ends of the base member 12
and the ends of the front outer seat frame member 26 are inserted
into respective ends of the center diagonal tension member 18.
Fastening screws 38, identical to the screws used with removable
sleeves 36, are then threaded into threaded holes at both ends of
tension member 18. Screws 38 are then threaded down snug against
the ends of the base member 12 and the front outer seat frame
member 26 until they are held firmly in place. Appropriate
indentations (not shown) can be provided in the base member 12 and
the front outer seat frame member 26 to receive fastening screws 38
and to insure positive engagement of the members by screws 38.
To collapse chair frame 34 screws 38 are loosened in removable
sleeves 36 and center diagonal tension member 18. Tension member 18
is then separated from chair frame 34. Removable sleeves 36 can be
removed from chair frame 34 or one side of the sleeve can be left
attached to the frame as shown in FIG. 13. The side compression
support members 14 and the seat back member 16 are attached
together by a pivot assembly 42 and can be folded substantially
parallel with cantilever seat frame 20. The pivot assembly, shown
assembled in FIG. 6 and in an exploded view in FIG. 5, includes a
fixed pivot plate 44 rigidly attached to cantilever seat frame 20
and a fixed pivot plate 46 rigidly attached to the side compression
support members 14. Pin 48 inserted through opening 50 in plate 46
and opening 52 in plate 44 holds cantilever seat frame 20 so it can
rotate relative to said compression support members 14. The
completely collapsed chair frame 34, shown in FIG. 13, includes
separated base member 12 and center diagonal tension member 18, and
folded cantilever seat frame 20, side compression support members
14, and seat back member 16.
In another alternate embodiment of the invention, the chair frame
can be provided as a completely foldable frame. Referring to FIG.
10, a foldable chair frame, generally designated 54, is shown.
Chair frame 54 is substantially the same as chair frame 34 in
geometry and operation. The only difference is that center diagonal
tension member 18 is connected to the front outer seat frame member
26 and the base member 12 by collars 56.
Collars 56, shown in cross-section in FIG. 11, are welded to the
ends of the front outer seat frame member 26 and the ends of the
base 12 inserted into the collars. The ends of the center diagonal
tension member 18 inserted into collars 56 are rotatably connected
to the collars. Referring to FIG. 11, this rotatable connection is
created by cutting a groove 58 around the circumference of the ends
of the tension member 18 that are inserted into collars 56. A
corresponding groove 60 is cut approximately half way around the
circumference of the collar that receives the grooved ends of the
tension member 18. The grooved ends of tension member 18 are
inserted into collars 56, and grooves 58 and 60 are lined up. A
C-clip 62 (shown in FIGS. 11 and 12), is then inserted into grooves
60 and clipped onto grooves 58 on the ends of tension member 18.
This allows collars 56 to freely rotate about the ends of tension
member 18.
When the chair frame 54 is to be stored the base member 12 is
separated from the side compression support members 14 at the
removable sleeves 36. The chair frame 54 is then folded
substantially flat as shown in FIG. 12.
There has thus been shown and described a novel chair frame which
fulfills all the objects and advantages sought. Many changes,
modifications, variations, and other uses and applications of the
subject invention, will become apparent to those skilled in the art
upon considering the specification and the accompanying drawings
which disclose the preferred embodiments. All such changes,
modifications, variations, and other uses and applications within
the spirit and scope of the invention are deemed to be covered by
the invention which is limited only by the claims which follow.
* * * * *